body {
  margin: 0px;
  background-image: url('../images/bataman-03.jpg');
  background-size: cover;
  background-repeat: no-repeat;
  background-attachment: fixed;
}

.backdorp {
  width: 20vw;
  height: 15vw;
  border-radius: 1rem;
  border: 1px solid #dcdcdc;
  display: flex;
  justify-content: center;
  align-items: center;
  color: #fff;
  font-size: 2rem;
  margin: 1rem;
  background-color: rgba(22, 7, 136, 0.1);
  backdrop-filter: blur(3px);
}

.i1:focus {
  background-color: #000;
  color: #fff;
}

/* 获取name属性为sex的input标签 +表示相邻下一个元素 */
input[name='sex'] + div {
  border: 1px solid #dcdcdc;
  margin: 1rem;
  padding: 0.2rem;
}

/* :checked表示该元素被选中 */
input[name='sex']:checked + div {
  color: #ff0000;
}
